Note: Descriptions are shown in the official language in which they were submitted.
-- I t67083
(1)
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to a trailer con-
nector and trailer for use in a truck and trailer
combination for carrying elongated self-supporting
loads, in particular to logging trucks and the
like.
Prior Art
Truck and trailer combinations for carry-
ing elongated sel-supporting loads have been used
for many years, particularly as logging trucks. In
the past, logging trucks were used extensively on
narrow and winding logging roads and, because the
bends in such roads were often relatively tight,
it was essential that the rear wheels of the trailer
follo~ed closely the tracking arc of the front
wheels of the tractor when negotiating the bends.
Modern logging trucks use a telescopic trailer
reach or compensator that extends rigidly forwardly
from the trailer and is hinged to a hitch disposed
rearwardly of the truck bunk. The truck bunk and
,. ,~.
,, .
1 ~ 6~
(2)
trailer bunk are both swivelling bunks and thus
tend to be somewhat unstable when the truck travels
at high speeds on the highway, The reach carries
negligible tensile loads when the logging truck
is loaded and serves mainly to force the rear wheels
of the trailer into an arc that appro~imates to the
front wheels of the trac~or as the truck negotiates
a curve. ~owadays logging roads have been improv~d
considerably, ie. widened and straightened, and
commonly semi-trailers or flatbed trailers can use
the main logging roads without much difficulty.
Consequently, trailer reaches as commonly used for
rear wheel tracking purposes are often not required,
Because trailer reaches are relatively
heavy components, ie. about three thousand to ~our
thousand pounds, they detract from payload of the
truck, It is well known to use a rear trailer to
support a rear end of a self-supporting load with
no connection between the rear trailer and tractor
apart from braking and electri.cal service conduits.
A "non-connected" trailer of this general type is
used on modern highways to transport excessively
long rigid loads, such as beams for bridges, build-
ings, etc, When the load is loaded onto thetractor and trailer, considerable care must be
I 1 670~3
(3)
exercised to ensure that the wheel axles of the
trailer are disposed normally to the central axis
of the tractor and trailer combination to ensure
accurate tracking of the rear wheels of the com-
bination.
Commonly, when loading this "non-connected"
type of tractor/trailer combination, several hours
might be required to adjust the relative disposi-
tion o~ the rear trailer by lateral shifting and
swivelling to ensure accurate wheel alignment.
Whilst such loading time might be acceptable for
transporting special loads where transportation
costs are not a major consideration, in the logging
industry where short turn around times are essen-
tial for econoMical operation, such excessive
~oading tlme would be uneconomic, A common logging
truck with a telescopic reach can be loaded within
minutes with no difficulty in maintaining wheel
alignment, and thus, prospective competitive
arrangements should be equally quick to load.
SUMMARY OF THE INVENTION
The invention reduces disadvantages of
1 ~ 670~3
(4)
the prior art by providing a trailer connector and
tractor for use in a tractor and trailer combina-
tion in which there is no rigid connection between
the tractor and trailer. The trailer connector is
S required only for initial trailer wheel alignment
prior to loading and because, when the combination
is loaded, the load itself,transmits towing and
turning forces. Thus the trailer connector can
be flexible and relatively lightweight as it carries
negligible loads when the combination is loaded, The
reduction in weight of the trailer connector and thus
the combination permits a considerable increase in
permissible load carrying capacity of the tractor
and tràiler combination, and also simplifies main-
tenance because negligible loads are imposed on thetrailer connector for most operations of the truck,
A trailer connector according to the
invention is for use in a tractor and trailer
combination for carrying an elongated, self-sup-
porting load. The tractor has a swivellable front
bunk mounted for pivotting about a pivot axis and
is adapted to retain a front portion of the load
thereon. The trailer has a rear bogey having at
least one pair of road bearing wheels and a non-
t ~ 67083
(5)
swivelling rear bunk mounted on the bogey andadapted to retain a rear portion of the load
thereon.
The trailer connector is further char-
acterized by flexible link means, a forward
connection means for connecting a forward end
portion of the flexible link means to the swivel- -
lable front bunk, and a rear connection means for
connecting a rear end portion of the link means
to the trailer. The link means and connection
means are arranged so that when the trailer is
unloaded and pulled by the tractor over a sub-
stantially level surface, a longitudinal central
axis of the trailer is aligned with the pivot axis
of the swivellable front bunk,
A method of the invention utilizing
structure as above described is characterized
by providing a flexible link and connecting a
forward end thereof to the swivellable front bunk
.and a rear end thereof to the trailer. The trac-
tor is moved forwardly while towing the trailer
through said flexible link until a central axis
of the trailer is aligned with the pivot axis
J 67083
(6)
of the swivellable front bunk. A self-supporting
load is placed on the front and rear bunks and
the front and rear portions of the load are
securely fastened to the front and rear bunks.
A detailed disclosure following, related
to drawings, describes preferred embodiments of
the invention which is capable of expression in
1~ structure other than that particularly described
and illustrated.
DESCRIPTION OF THE DRAWINGS
Fig. 1 is a simplified diagrammatic side eleva-
tion of a tractor and trailer combination
using one embodiment o a trailer connect-
or according to the inventlon,
Fig. 2 is a simplified diagrammatic top plan of
the embodiment of Fig. 1,
I 1 67083
(7)
Fig. 3 is a simplified rear elevation of the
trailer of Fig. l,
Fig. 4 is a simplified fragmented top plan of a
central portion of the trailer connector
of Fig, 1,
Fig. 5 is a simplified fragmented side elevation
of the central portion of the trailer
connector shown in Fig~ 4,
Fig, 6 is a simplified fragmented top plan of a
rear portion of the trailer connector
of Fig. 1,
Fig. 7 is a simplified fragmented side elevation
of the rear portion of the trailer connect-
or shown in Fig. 6,
0 Fig. 8 is a simplified fragmented section on
line 8-8 of Fig. 2 showing stabili~ing
link anchoring means,
Fi8~ 9 is a simplified diagrammatic top plcln of
``~ 7~3
(8)
a second embodiment of a trailer and trailer
connector,
Fig. lO (which appears on the same page as Fig, 3)
is a simplified fragmented side elevation
of the alternative trailer and a portion
of the trailer connector of Fig. 9,
Fig. ll (which appears on the same page as Fig. 3)
is a simplified fragmented side elevation
of a trailer similar to the trailer of
Fig. 1 showing an alternative stabilizing
link anchoring means,
Fig. 12 is a simplified diagrammatic side eleva-
tion of a third embodiment of a trailer
connector according to the invention,
Fig. 13 is a simplified diagrammatic top plan of
a third embodiment of Fig. 12,
Fig. 14 (which appears on the same page as Fig. 3)
is a simplified diagrammatic top plan of
a fourth embodiment of a trailer connect-
or using the trailer of Figs. 9 and 10,
Fig. 15 (which appea~s on the same page as Fig. 3)
is a simplified diagrammatic top plan of
a tractor and douhle trailer combination
utilizing the first embodiment of the
,
,
I ~ 670~3
(9)
trailer connector of Figs. i through 3.
DETAILED DISCLOSURE
Fi~s. 1 through 3
A tractor and trailer com~ination 10
according to the invention has an essentially
conventional tractor 11 and a modified trailer
12, the trailer being connected to the tractor by
a trailer connector 14 according to the invention.
The tractor is a typical prior art logging truck
tractor having a swivellable front bunk 17 mounted
for pivottlng about a vertical pivot axis 18
~ disposed over a set of rear wheels 20 mounte~d on
- twin or tandem axles. The traller 12 has a simi-
lar set of tandem wheels 22 mounted on a trailer
frame 24 and is termed a rear bogey, the frame
carrying a non-swivelling rear bunk 26 mounted on
the bogey. The front and rear bunks have pairs
of spaced stakes 29 and 30 respectively to support
a load of logs 32, broken outline, extending
therebetween, The stakes and bunks are generally
similar to the prior art except that the rear bunk
is mounted rigidly, that is non-swivellably on the
1 3 67~3
(10)
rear trailer for reasons to be explained, and thus
contrasts with the swivelling rear bunk on common
trailers. Loads other than logs can be carried
between the bunks, such as,concrete or steel beams,
etc., p~ovided the load is eloMgated and self-sup-
porting so as to permit supporting of the load
at positions adjacent either end so that the ~ront
and rear portions of the load are retained on the
front and rear bunks respectively.
The trailer has a walking beam 35
carrying trailer axles for pairs of the wheels
22 spaced longitudinally at opposite ends of the
beam on each side of the trailer. The beam is
hinged to'a lower portion of the frame so as to
pivot about a transverse beam axis 37 disposed
; parallel to the trailer axles as is weLl known in
the prior art. As illustrated, the walking beam
thus provides a simple and rugged suspension for
. 20 the rear traiLer and is similar to that commonly
used on logging trucks, The walking beam 35 is
thus a longitudinal suspension means extending
between the wheels, and the frame is hinged to
the suspension means for longitudinal rocking
movement in a forward and rearwards manner rela-
tive to the wheelsO
`` I 1 670~3
(11)
The trailer connector 14 has right hand
and left hand forward link portions 41 and 42
extending rearwardly from cable anchors 39 at
opposite ends of the front bunk 17 to a loop
S connector 44 disposed approximately midway bet-
ween the front and rear bunks, ie. generally adja-
cent a central portion of the connector 14. The
connector 14 also has right hand and left hand
rear link portions 47 and 48 extending forwardly
from cable anchors 49 at laterally spaced posi-
tior~s on the trailer 12 to connect similarly a~
the loop connector 44. A stabilizing link 51
extends from a forward end at the loop connector
to a rear end secured to a cable anchor 55 on the
15' frame 24, The stabilizing link 51 passes around
a pulley 53 mounted on a portion of the trailer
spaced beneath a straight line 57 extending bet-
ween rear connections of the rear link portions
with the trailer, as will be described with ref-
erence to Fig. 8, Without the stabilizing linkwhen the trailer is unloaded it would otherwise
be free to rock longitudinally about the beam
axis 37, Therefore, the stabilizing link 51 is
required in cooperation with the link portions
47' and 48 to provide three spaced suppor~s to
prevent uncontrolled rocking of the trailer frame
I ~ 67083
~12)
24 relative to the wheels 22. It can be seen
that the loop connector 44 is 3 in fact, a joining
means to join the forward link portions to the
rear link portions and also the stabilizing link
to the forward and rear link portions, and in
some circumstances can be eliminated, or equiva-
lents can be substituted, as will be described.
The link portions 41, 42, 47 and 48
and the stabilizing link 51 are all suitably
flexible steel cable of a diametcr of between
0.5 cm. and 2 cm. and thus have sufficient
strength to hold the rear trailer when unloaded
and yet resist any tendency to form permanent
kinks resulting from excessive non-elastic bend-
ing of the cable. If a length of cable becomes
damaged, for example by a truck running over the
cable such that the cable does not straighten
under light loads, it should he discarded other-
wise it will shorten effective length of thecable. The trailer connector 14 is used primar-
ily to align the axles of the trailer with the
rear axles of the tractor prior to loading logs
onto the bunks.
The front and rear link portions, the
I ~ G70(~3
(13)
stabilizing link and loop connector 44 are all
disposed symmetrically about a central longitudi-
nal axis 59 of the combination 10, and thus it
can be seen t~at the trailer connector 14 is a
connector Link means extending symmetrically
about the central longitudinal axis between at
least two laterally spaced positions on the front
bunk and at least two laterally spaced positions
on the trailer.
The rear bunk 26 has a transversely
extending row of teeth or serrations 62 extending
between the stakes 30, and front and rear portions
of the trailer frame 24 have similar sets of
teeth or serrations 64 and 65 respectively dis-
posed so aY to be at a similar height to the
teeth 62. Tie down cables 63 draw the logs onto
the teeth 62, 64 and 65 to augment restraint o~
rear ends of the logs on the trailer due to dead
weight of the log. Clearly, if a load other than
logs were to be carried, the teeth or serrations
62, 64 and 65 would be modified to be appropriate
for the load. In any event, means to reduce a
tendency of the load to shift relative to the rear
trailer is provided so as to maintain alignment
of the trailer axle or axles relative to line of
~ . ,
I ~ ~7033
travel of the combination, that is the trailer
axle sl~ould at all times be disposed normally to
and symmetrically of the longitudinal axis 59.
Pintle and gudgeon means 66 or equivalents there-
of are fitted at a rear end of the tractor 11 and at a for-
ward end of the trailer 12 for towing the trailer behind the
tractor when unloaded. This is an alternative to the common
"piggybackl' method of carrying an unloaded logging trailer,
although "piggyback" carrying is easy with this invention
because trailer service conduits do not require disconnection~
Figs. 4 and 5
The loop connector 44 is an annulus adapted
to receive eyes fitted to ends of the cables repre-
senting the forward link portions 41 and 42 ~ the
rear link portions 47 and 48, and the stabilizing
link portion 51. Referring to Fig 5, the left hand
forward and rear link portions 42 and 48 have res-
pective eyes 6~ and 69 forrned at ends of the respec-
tive link portions and secured by c~lindrical ferrules
71 and 72 respectively. Openings of the eyes can be
reinforced with bushings (not shown) if desired, to
prevent excessive wear of the cables on the loop
connector 44r As seen in Fig. 4, the connector 44
is formed from two semi-circular half portions 73
6~0~3
, (15)
and 74 connected together by nut and bolt means 75
to permit easy connection and disconnection of the
link portions, thus serving as a releasable cable
connecting means, Opposite ends of all the link
portions are similarly provided with eyes secured by
ferrules, as shown in Fig. 5, Other means to permit
easy connection and disconnection of link portions
can be substi~uted.
Figs. 6 and 7
The cable anchor 39 for one link portion is
as follows. A rear end of the left hand link portion
48 is connected to a portion of the trailer spaced
from the longitudinal axis 59, as shownO The link
portion 48 has an eye 76 secured by a ferrule 77 in
a manner similar to that previously Jescrlbed~ A
portion of the traller frame 24 is shown and has a
bracket 79 extending from a corner somewhat forward
of the wheels 22, a portion of one wheel being shown.
An eye bolt 80 has an eye 81 at a forward end thereof
and a threaded shank 82 received in a clearance open-
ing passing through the bracket 79. The clearance
opening in the bracket permits the bolt 80 to align
itself with the link portion 48, thus reducing ~r
eliminating bending loads on the bolt 80. Nut and
t - washer means 83 and ~4 are fitted on opposite sides
.. . .. .. .
I l ~70S3
- (16)
of the bracket 79 and it can be seen that by loosen-
ing one nut and tightening the other nut, the eye
bolt 80 can be moved longitudinally according to
an arrow 85. This provides a fine adjustment for
length of the link portion 48, as well as provid-
ing an economical and simple means of securing
the link portion to the trailer.
, Forward ends of the forward link portions
41 and 42, see Fig, 2, can be similarly secured to the
anchors 39 at opposite ends of the front bunk 17
with similar bracket, eye bolt and nut and washer
means to provide similar accurate adjustment of
length of the forward link portions also. The
stabilizing link portion 51 has a rear end simi-
larly connected to the trailer, but the associated
bracket extends from the trailer adjacent the
longitudinal axis 59. Thus effective length of
each of the link portions can be adjusted accur-,
ately an adequate amount to permit accurate loca-
tion of the loop connector 44 relative to the
axis 59 of the combination 10. Clearly, prior to
use, an accurate ali~nment of the trailer axles
with the tractor axles is required. This align-
ment is accomplished with the combination parkedon smooth level ground and the rear trailer is
~ l 670~3
(17)
manually positioned in the approximate location
rearwardly of the tractor. Conventional alignment
measurements are taken and the nut and bolt means
are adjusted to provide fine adjustment of the
cable length following, in general, normal align-
ment practice in maintenance yards.
Figo 8
The trailer frame 24 is shown broken and
diagrammatically to illustrate the effect of the
stabilizing link portion 51 and the pulley 53
relative to the beam axis 37. Without the res-
traint of the load and the link portions 47, 48
and 51 on the rear trailer, the frame and bunk
would be free to rock longitudinally about the
beam axis 37 which serves as a transverse rocker
axis for the trailer, This is termed a "rocking"
trailer. With no load on the trailer 12, tension
in the link portions 47 and 48 would apply a turn-
ing moment on the frame 24 about the axis 37 in
direction of an arrow 87 ~ and tension in the stab-
ilizing link portion 51 through the pulley 53 and
cable anchor 55 applies a turning moment in an
opposite direction in accordance with an arrow 88
It can be seen that, by fine adjustment of the
7~$3
(18)
length of the appropriate link portions, and thus
resulting tension, the frame 24 can be stabilized
against the rocking tendency that would otherwise
occur prior to loading.
s
In summary, the pulley 53 is positioned within
a central plane containing the longitudinal a~is 59 (Fig.
2 only) and is spaced beneath the straight line 57 ex-
tending between the rear connections of the link
portions, The stabilizing link passes downwardly
and rearwardly beneath the pulley 53 and then
upwardly to the rear connection at the anchor 55
positioned within the central plane and disposed
rearwardly of the pulley, Thus, the pulley and
position of the rear anchor serve as counteract-
ing means 89 on the trailer cooperating with the
stabilizing link portion 51 to counteract a turn
ing moment applied by the rear link portions to
the trailer, It can be seen that the actual loca-
tion of the pulley 53 and the anchor 55 is notcrltical provided there is sufficient vertical
spacing between the rear connections of the rear
link portions and the pulley, although the pulley
is not required to be positioned directly verti-
cally beneath the straight line 57 connecting thetwo cable anchors 49, Also, it is not necessary
~ 1 6~0~
(19)
~hat the anchor 55 is aligned horizontally with
the rear link portions as shown. Optimum position
of the pulley 53 and anchor 55 would be dependent
on geometry of the rear trailer, in particular the
location of the beam axis 37 and moment arm of
force from the rear link portions relative to the
beam axis.
OPERATIoN
The trailer connector 14 according to
the invention permits easy alignment o the trailer
axle prlor to loading logs onto the bunks, assum-
ing that there has been accurate adjustment oflink portion lengths as previously described.
After the alignment, the connector 14 serves little
purpose apart from that of a redundant safety
connection between the trailer and the tractor,
and also for providing support for electrical,
pneumatic and hydraulic service conduits, not show
shown, extending between the tractor and trailer.
At a log loading station, the tractor
Z5 and trailer are positioned under the log loader,
not shown, and all that is required is that the
(20)
wheels 22 of the trailer run initially on rela-
~ively smooth and level ground so as to reduce any
tendency of the ~railer wheels to move assymmetri-
cally as the tractor moves forwardly. The ~ractor
moves forwardly for a few Eeet so that the link
portions 41, 42, 47, 4& and 51 become taut, at
which time the rear bunk 26 will be essentially
parallel to the front bunk 17. This is performed
slowly so that as the brakes are applied, the
wheels of the trailer are braked evenly and
slowly so that the bunks remain parallel when
both the tractor an~ trailer stop, thus maintain-
ing approximately equal tautness in all the links.
If the trailer has independent braking 5 it may be
advantageous to brake the trailer somewhat before
the tractor so as to assist in maintaining taut-
ness of the cables. The brakes are now set on
both the tractor and trailer and placement o~
wheel chocks at the trailer wheels may be advan-
tageous to prevent undesirable shifting. Alter-
natively, particularly on slippery or slightly
sloping ground, in a non~illustrated alternative,
a cable can be connected between a rear of the
trailer and a winch or other type of towing
vehicle, such as a skidder, and the trailer can
~ 1 670~3
(21)
then be pulled sufficiently away from the tractor
to tauten the link portions to permit accurate
length adjustment thereofO
The tractor and trailer combination is
now ready to accept logs which can be loaded bet-
ween the front and rear bunks in a normal manner.
When loaded, the logs are retained with the tie
down cables 63 as required and longitudinal move-
ment of the logs is reduced or eliminated by the
serrations which is the normal practice with log-
ging trucks.
It can be seen that this approach to
alignment ~f tractor wheels is considerably
quicker and simpler than in the prior art where
the "unconnected" trailer is "manually" posi-
tioned accurately each time ~he combination is
loaded. With this invention, the trailer is
pogitioned accurately "manually" once only when
the link portions are adjusted, after which the
alignment i8 e~ected automatically by the link
portions.
.
6~83
(22)
It can be seen that the method according
to the invention is characterized by providing a
flexible link means and connecting one end of the
flexible link means to the swivellable front bunk
and an opposite end thereof to the trailer. The
tractor is moved forward whilst towing the trailer
through the link means until a longitudinal cen-
tral axis of the trailer, which is undesignated
but coincident with the axis 59, is accurately
aligned with the pivot axis of the swivellable
front bunkO The self-supporting load is placed
on the front and rear bunks and the front and
rear portions of the load are securely fastened
to the front and rear bunks.
ALTERNATIVES AND EQUIVALENTS
Fi~s. 9 and 10
A second embodiment of a trailer 91 has
a trailer bunk 93 having spaced stakes 94 which
3 ~70~3
2 3)
are similar to those previously described. The
trailer 91 has a trailer frame 96 mounting a con-
ventional tandem axle trailer suspension 9~ uti-
lizing sets of resilient springs 99. The frame
96 and suspension is such that there is a negli-
gible rocking tendency between the wheels and the
frame and thus is termed a "non-rocking" trailer.
With a non-rocking trailer, the stabilizing link
51 of the connector 14 of Figso 1 through 8 can
be eliminated. This provides a simpler alterna-
tive second embodiment of a trailer connector,
designated 101, which is limited for use on
trailers having a suspension and frame such that
there is negligible rocking therebetween, apart
from that occuring with normal suspension ~eflec-
tion.
The trailer connector 101 lncludes right
hand and left hand forward link portions 103 and
104 connected to a swivellable front bunk 100 on
the tractor, not shown, and right hand and left
hand rear link portions 105 and 106 connected to
1 1 6~083
(24)
the trailer 91. An intermediate link portion 108has forward and rear loop connectors 109 and 110
at forward and rear ends thereof. The forward
link portions are connected to the forward loop
connector, and the rear link portions are connected
to the rear loop connector. Ends of the link
portions are provided with eyes that cooperate
with the loop connectors, and with ring bolts
(not shown) mounted in brackets carried on the
trailer 91 and the forward bunk in a manner simi-
lar to that previously described with reference
to Figs. 5 through 7.
It can be seen that the intermediate link
portion 10~ extends along a central axis 111 of
the combination so as to provide a symmetrical
arrangement. A particular advantage for use of
an intermediate link portion is that a turnbuckle,
not shown, or equivalent length adjustment means
can be provided to cooperate with the intermediate
link to permit easy length adjustment without
adjusting the eye bolts associated with the trailer
or front bunk. This prevents a possible loss of
alignment that mi~ht otherwise occur if the ring
1 1 670~3
(25)
bolts were adjusted. Alternatively, intermediate
links of different lengths could be fitted between
the loop connectors to accomodate loads of widely
differing lengths. The intermediate link also
serves as a joining means to join the forward
link portions to the rear link portions.
Clearly, if desired, the trailer connector
101 could be provided with a stabilizing link por-
tion extending between the rear loop connector llOand the trailer in a manner similar to ~he link
portion 51 of Figs. 1 through 3, and this would
then permit use of a "rocking" trailer in which
the frame thereof could rock relative to the sus-
pension similarly to the trailer 12.
Fig. 11
An alternative "rocking" trailer 113 is
generally similar to the trailer 12 of Figs. 1through 8, but differs by elimination of the
pulley 53 and by substituting an upwardly curved
walking beam 114 for the beam 35. The beam 114
is journalled on a trailer frame 115 for rocking
about a rocker axis or beam a~is 116, as previous-
ly described. An alternative means to counteract
~70~3
(26)
a rocking tendency of the alternative rocking
trailer includes a downwards extension 117 extend-
ing from a portion of the frame 115 to a cable
anchor 118 which is disposed within a central
plane containing a central longitudinal axis,
neither of which are shown, and below and forwardly
of the rocker axis 116. The anchor 118 is con-
nected to a rear end of the stabilizing link por-
tion 51 which is thus positioned forwardly of and
below the rocker axis and within the cen~ral plane.
The rear link portions 47 and 48 (of Figs. 1 through
8) have rear connections or anchors positioned
above the rocker axis and apply a turning moment
to the frame about the axis 116 in direction of
an arrow 112. The stabilizing link portion 51
applies an cpposite turning molnent to the frame
in direction of an arrow 119. Thus it can be seen
that by accurate adjustment of the appropriate
link lengths, the trailer can be stabilized against
excessive rocking. It can be seen that the down-
wards extension 117 and the location of the cable
anchor 118 cooperating with the stabilizing link
portion is thus equivalent to the pulley 53 and
cable anchor 55 of Fig. 1, and thus serve as
counteracting means on the trailer cooperating
with the stabilizing link to counteract a turning
~ ~ 6~S3
(27)
moment applied by the rear link portions to the
trailer.
Figs. 12 and 13
A third embodiment of a trailer connector,
designated 120, is shown for use with a trailer 122
which is generally similar to the trailer 91 of
Figs. 9 and 10, ie, a non-rocking trailer. How-
ever, as described with reference to Figs. 9 and10, if a stabilizing link portion or equivalent
were fitted, with suitable modification, the
trailer connector 120 could be used with the rock- '
ing trailer 12 of Figs. 1 through 3. A tractor,
not shown, has a ront bunk 126 having spaced
stakes 127 and is mounted for pivotting about an
axis 128,
The trailer connector 120 :includes a
single flexible cable serving as a main flexible
tension link portion 130 having a forward end 131
secured centrally of the bunk and a rear end 132
secured centrall,y of,the trailer, The front bunk
has a forward alignment frame 134 extending rear-
wardly therefrom, the frame having a front eye135 to accept the cable of the portion 130. The
~ ~ 67~3
(28)
frame 134 has right hand and left hand struts 136
and 137 respectively extending from positions
spaced equally from the axis 12& to provide a
support for the eye 135 that resists sideways and
vertical deflections. It can be seen that the
alignment frame swings about the pivot axis 128
as the front bunk 126 swivels about the axis. The
trailer has a rear alignment frame 138 extending
rigidly and forwardly from the trailer, the frame
13~ being similar to the frame 134 and having a
rear eye 139 therein to accept the link portion
130.
The frames 134 and 13~ are forward and
rear alignment means provided on the front bunk
and trailer respectively. The frames are disposed
symmetrically about a central longitudinal axis
125 and function in a manner similar to the right
hand and left hand forward and rear link portions
o the embodiments shown in Figs. 1 through 3 and
Figs, 9 and 10,
An alterna~ive structure using the align-
ment frames as above described could secure forward
and rear ends of the portion 130 directly to the
alignment frames themselves, thus eliminating ~he
- I 1 6~083
(29)
direct connection of the link portion to the front
bunk and trailer. The alternative frames would
thus carry tensile forces also, and would likely
have to be stronger than the ~rames that merely
provide guiding eyes for the cable. Both of
these structures could utilize a flexible tension
link, preferably a cable, although a link chain
could be used in some circumstances. It would be
expected that the trailer using the rigid align-
ment frames as above described would have aslower response for alignment than the cable con-
nectors of Figs. 1 through 3 and Figs. 9 and 10.
Fi~. 14
A fourth embodiment of a trailer con-
nector 140 extends between a swivellable front
bunk 141 mounted on a tractor, not shown, and
the trailer 91 of Fig. 10. Because l;he trailer
91 is a non-rocking trailer, a stabilizing link
portion or equivalent is not required. The fourth
embodiment 140 has a central longitudinal axis
142 and first and second diagonal link portions
143 and 144 of generally equal length. The link
portions cross each other at an intersection 145
which is generally adjacent the central longitudi-
~70~3
(30)
nal axis 142. For improved tracking, the links canbe clamped at the intersection with a cable clamp
145.1, but in some conditions acceptable performance
can be obtained with the link portions not connected
at this intersection but merely passing each other
in a vertical plane. The first link portion 143
extends from a right hand end of the front bunk 141
to a left hand portion of the trailer 91, and the
second link portion extends from a left hand front
bunk to a right hand portion of the trailer. Connec-
tions at opposite ends of the link portions are gene-
rally similar to those as previously described,
and suitable adjustment means are provided to
permit fine adjustment of the length of the link
portions. It can be seen that this is one of
the simplest embodiments of the trailer connector
and, as shown, it can only be used with a non-
rocking trailer, When the links a~e unclamped at
the intersection 145, there is usually essentially
zero relative axial movement between the link
portions 143 and 144, but this arran~ement is not
preferred for most situations. When the link
portions are clamped at 145.1, the clamp means can
then be used as an anchor for a forward end of a
stabilizing link portion, which could extend to a
~67~3
(31)
substitute trailer which could be of the rocking
type, and similar to that described with re~erence
to Fig. 1, This alternative is not illustrated,
but is clearly an equivalent,
Fig. 15
An alternative tractor and trailer
combination 146 utilizes a conventional tractor
147 with a swivellable front or first bunk 148
mounted for swivelling on the tractor as pre-
viously described, An intermediate trailer 150
is connected to the tractor by first trailer
connecting means 152 which extend from the front
bunk to a forward portion of the trailer 150. The
trailer 150 has a fixed intermediate trailer front
bunk 154, and a swivellable intermediate trailer
rear bunk 156 and is carried on a tandem axle
arrangement 158 so as to provide a solid, essen-
tially non-rocking bed for the bunks 154 and 156.
A rear trailer 160 is connected to the intermediate
trailer 150 by second trailer connecting means 162
extending from the rear bunk 156 to a front of the
trailer 160. The trailer 160 is similar to the
non-rocking trailer 91 of Figs. 9 and 10, and has
a tandem axle arrangement 164 and a ~ixed second
1 3 67083
(~2)
trailer rear bunk 166. The first and second
trailer connecting means 152 and 162 include
undesignated front and rear link portions, gene-
rally similar to that shown in Figs. 1 through 3,
but the alternatives herein described can be sub-
stituted,
The combination 146 can carry two separate
self-supporting front and rear loads 167 and 168
shown in broken outline, the loads being mounted
between the bunks 14~ and 154, and between the
bunks 156 and 166 respectively. Clearly, to prevent
interference when turning, sufficient clearance
must be provided between adjacent ends of the loads
overhanging the bunks on the intermediate trailer 150.
In summary, all embodiments of the trailer
connector use lengths of flexible steel cable and
conventional cable connections, etc., and thus the
capital investment for the connector is relatively low.
The embodiments of the trailer can be obtained by
eliminatLng the trailer reach and swivellable bunk of
a conventional logging trailer and substituting cable
anchors and a fixed or non-swivelling bunk. The
connector is used as a support for trailer service
conduits. The fixed trailer bunk helps to stabilize
1 3 670~ 3
(33)
the load against wobble that can occur wi~h two
swivelling bunks.
Summarizing the embodimen-ts structurally,
it can ~e seen that the invention provides a flex-
ible link means with a forward connection means for
connecting a forward end portion of the flexible
link means to the swivellablé front bunk, and a rear
connection means for connecting a rear end portion
of the flexible link means to the trailer. It can
be seen that the forward and rear connection means
have several different structures, for example, the
forward link portions 41 and 42 and the rear link
portions 47 and 48 of Figs. 1 and 2, the corres-
ponding link portions of Fig. 9, the forward andrear alignment frame 134 and 138 of Figs. 12 and
13 and the diagonal link portions 143 and 144 of
Fig. 14. All these structures are considered to
function equivalently and require that the forward
connection means have forward portions cooperating
with two laterally spaced positions on the swivel-
lable front bunk, and the rear connection means
cooperating with two laterally space~d positions on
the trailer~ The positions on the bunk for the
forward connection are spaced equally from the
central longltudinal axis, and the positions on
~70~3
(34)
the trailer for the rear connection are similarly
spaced equally from the longitudinal axis.
